In cooling a load, for example, with this type of circulating apparatus, a coolant as a constant temperature liquid a temperature of which is adjusted is housed in a tank and the coolant is supplied to the load through piping by a pump in a circulating manner to thereby cool the load. The coolant the temperature of which rises due to cooling of the load and which flows back into the tank exchanges heat with a refrigerant in a heat exchanger to thereby adjust the temperature.
The load is normally connected to the circulating apparatus through piping prepared by a user. A kind, a disposition place, and the like of the load are different depending on users. Therefore, if flow path capacities in the piping and the load are large, a liquid level in the tank may lower by a large amount when operation of the circulating apparatus starts to supply the coolant to the piping and the heat load. In some cases, there is a fear that the reduction in the liquid level in the tank provides a hindrance to operation of the pump.
On the other hand, it is preferable to recover all the coolant filling the load and the piping connecting the apparatus and the load into the tank when the operation of this circulating apparatus is completed or at the time of maintenance, inspection, or the like of the apparatus. However, if the coolant of such an amount that a proper liquid level is obtained in the tank in a steady operating state of the apparatus has been used, all the coolant may not be housed in the tank and the coolant may overflow from the tank in recovering the coolant depending on the flow path capacities in the piping and the load.
Therefore, in order to solve such problems, there is an apparatus in which a liquid level regulating chamber is provided in a tank and communicates through a bottom portion thereof with inside of the tank, compressed gas is supplied to and discharged from the liquid level regulating chamber to cause a constant temperature liquid to flow out from the liquid level regulating chamber into the tank or flow from the tank into the liquid level regulating chamber to thereby regulate a liquids level of the constant temperature liquid in the tank as disclosed in Japanese Patent Application Laid-open No. 2002-181427 (JP-A).
This circulating apparatus has advantages that the liquid level of the constant temperature liquid in the tank does not change by a large amount when the operation starts or is completed and that a small amount of constant temperature liquid can efficiently be utilized.